/*
 * jPOS Project [http://jpos.org]
 * Copyright (C) 2000-2015 Alejandro P. Revilla
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.jpos.iso;

import java.math.BigDecimal;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.text.DecimalFormat;
import java.util.*;

/**
 * various functions needed to pack/unpack ISO-8583 fields
 *
 * @author apr@jpos.org
 * @author Hani S. Kirollos
 * @author Alwyn Schoeman
 * @version $Id$
 * @see ISOComponent
 */
@SuppressWarnings("unused")
public class ISOUtil {
	/**
	 * All methods in this class are static, so there's usually no need to instantiate it
	 * We provide this public constructor in order to deal with some legacy script integration
	 * that needs an instance of this class in a rendering context.
	 */
	public ISOUtil() {
		super();
	}

	public static final String[] hexStrings;

	static {
		hexStrings = new String[256];
		for (int i = 0; i < 256; i++) {
			StringBuilder d = new StringBuilder(2);
			char ch = Character.forDigit((byte) i >> 4 & 0x0F, 16);
			d.append(Character.toUpperCase(ch));
			ch = Character.forDigit((byte) i & 0x0F, 16);
			d.append(Character.toUpperCase(ch));
			hexStrings[i] = d.toString();
		}

	}

	/**
	 * Default encoding (charset) for bytes transmissions over network
	 *
	 * @deprecated use {@link #CHARSET} instead
	 */
	public static final String ENCODING = "GB18030";

	/**
	 * Default charset for bytes transmissions over network
	 */
	public static final Charset CHARSET = Charset.forName("GB18030");

	public static final byte[] EBCDIC2ASCII = new byte[]{
			(byte) 0x0, (byte) 0x1, (byte) 0x2, (byte) 0x3,
			(byte) 0x9C, (byte) 0x9, (byte) 0x86, (byte) 0x7F,
			(byte) 0x97, (byte) 0x8D, (byte) 0x8E, (byte) 0xB,
			(byte) 0xC, (byte) 0xD, (byte) 0xE, (byte) 0xF,
			(byte) 0x10, (byte) 0x11, (byte) 0x12, (byte) 0x13,
			(byte) 0x9D, (byte) 0xA, (byte) 0x8, (byte) 0x87,
			(byte) 0x18, (byte) 0x19, (byte) 0x92, (byte) 0x8F,
			(byte) 0x1C, (byte) 0x1D, (byte) 0x1E, (byte) 0x1F,
			(byte) 0x80, (byte) 0x81, (byte) 0x82, (byte) 0x83,
			(byte) 0x84, (byte) 0x85, (byte) 0x17, (byte) 0x1B,
			(byte) 0x88, (byte) 0x89, (byte) 0x8A, (byte) 0x8B,
			(byte) 0x8C, (byte) 0x5, (byte) 0x6, (byte) 0x7,
			(byte) 0x90, (byte) 0x91, (byte) 0x16, (byte) 0x93,
			(byte) 0x94, (byte) 0x95, (byte) 0x96, (byte) 0x4,
			(byte) 0x98, (byte) 0x99, (byte) 0x9A, (byte) 0x9B,
			(byte) 0x14, (byte) 0x15, (byte) 0x9E, (byte) 0x1A,
			(byte) 0x20, (byte) 0xA0, (byte) 0xE2, (byte) 0xE4,
			(byte) 0xE0, (byte) 0xE1, (byte) 0xE3, (byte) 0xE5,
			(byte) 0xE7, (byte) 0xF1, (byte) 0xA2, (byte) 0x2E,
			(byte) 0x3C, (byte) 0x28, (byte) 0x2B, (byte) 0x7C,
			(byte) 0x26, (byte) 0xE9, (byte) 0xEA, (byte) 0xEB,
			(byte) 0xE8, (byte) 0xED, (byte) 0xEE, (byte) 0xEF,
			(byte) 0xEC, (byte) 0xDF, (byte) 0x21, (byte) 0x24,
			(byte) 0x2A, (byte) 0x29, (byte) 0x3B, (byte) 0x5E,
			(byte) 0x2D, (byte) 0x2F, (byte) 0xC2, (byte) 0xC4,
			(byte) 0xC0, (byte) 0xC1, (byte) 0xC3, (byte) 0xC5,
			(byte) 0xC7, (byte) 0xD1, (byte) 0xA6, (byte) 0x2C,
			(byte) 0x25, (byte) 0x5F, (byte) 0x3E, (byte) 0x3F,
			(byte) 0xF8, (byte) 0xC9, (byte) 0xCA, (byte) 0xCB,
			(byte) 0xC8, (byte) 0xCD, (byte) 0xCE, (byte) 0xCF,
			(byte) 0xCC, (byte) 0x60, (byte) 0x3A, (byte) 0x23,
			(byte) 0x40, (byte) 0x27, (byte) 0x3D, (byte) 0x22,
			(byte) 0xD8, (byte) 0x61, (byte) 0x62, (byte) 0x63,
			(byte) 0x64, (byte) 0x65, (byte) 0x66, (byte) 0x67,
			(byte) 0x68, (byte) 0x69, (byte) 0xAB, (byte) 0xBB,
			(byte) 0xF0, (byte) 0xFD, (byte) 0xFE, (byte) 0xB1,
			(byte) 0xB0, (byte) 0x6A, (byte) 0x6B, (byte) 0x6C,
			(byte) 0x6D, (byte) 0x6E, (byte) 0x6F, (byte) 0x70,
			(byte) 0x71, (byte) 0x72, (byte) 0xAA, (byte) 0xBA,
			(byte) 0xE6, (byte) 0xB8, (byte) 0xC6, (byte) 0xA4,
			(byte) 0xB5, (byte) 0x7E, (byte) 0x73, (byte) 0x74,
			(byte) 0x75, (byte) 0x76, (byte) 0x77, (byte) 0x78,
			(byte) 0x79, (byte) 0x7A, (byte) 0xA1, (byte) 0xBF,
			(byte) 0xD0, (byte) 0x5B, (byte) 0xDE, (byte) 0xAE,
			(byte) 0xAC, (byte) 0xA3, (byte) 0xA5, (byte) 0xB7,
			(byte) 0xA9, (byte) 0xA7, (byte) 0xB6, (byte) 0xBC,
			(byte) 0xBD, (byte) 0xBE, (byte) 0xDD, (byte) 0xA8,
			(byte) 0xAF, (byte) 0x5D, (byte) 0xB4, (byte) 0xD7,
			(byte) 0x7B, (byte) 0x41, (byte) 0x42, (byte) 0x43,
			(byte) 0x44, (byte) 0x45, (byte) 0x46, (byte) 0x47,
			(byte) 0x48, (byte) 0x49, (byte) 0xAD, (byte) 0xF4,
			(byte) 0xF6, (byte) 0xF2, (byte) 0xF3, (byte) 0xF5,
			(byte) 0x7D, (byte) 0x4A, (byte) 0x4B, (byte) 0x4C,
			(byte) 0x4D, (byte) 0x4E, (byte) 0x4F, (byte) 0x50,
			(byte) 0x51, (byte) 0x52, (byte) 0xB9, (byte) 0xFB,
			(byte) 0xFC, (byte) 0xF9, (byte) 0xFA, (byte) 0xFF,
			(byte) 0x5C, (byte) 0xF7, (byte) 0x53, (byte) 0x54,
			(byte) 0x55, (byte) 0x56, (byte) 0x57, (byte) 0x58,
			(byte) 0x59, (byte) 0x5A, (byte) 0xB2, (byte) 0xD4,
			(byte) 0xD6, (byte) 0xD2, (byte) 0xD3, (byte) 0xD5,
			(byte) 0x30, (byte) 0x31, (byte) 0x32, (byte) 0x33,
			(byte) 0x34, (byte) 0x35, (byte) 0x36, (byte) 0x37,
			(byte) 0x38, (byte) 0x39, (byte) 0xB3, (byte) 0xDB,
			(byte) 0xDC, (byte) 0xD9, (byte) 0xDA, (byte) 0x9F
	};
	public static final byte[] ASCII2EBCDIC = new byte[]{
			(byte) 0x0, (byte) 0x1, (byte) 0x2, (byte) 0x3,
			(byte) 0x37, (byte) 0x2D, (byte) 0x2E, (byte) 0x2F,
			(byte) 0x16, (byte) 0x5, (byte) 0x15, (byte) 0xB,
			(byte) 0xC, (byte) 0xD, (byte) 0xE, (byte) 0xF,
			(byte) 0x10, (byte) 0x11, (byte) 0x12, (byte) 0x13,
			(byte) 0x3C, (byte) 0x3D, (byte) 0x32, (byte) 0x26,
			(byte) 0x18, (byte) 0x19, (byte) 0x3F, (byte) 0x27,
			(byte) 0x1C, (byte) 0x1D, (byte) 0x1E, (byte) 0x1F,
			(byte) 0x40, (byte) 0x5A, (byte) 0x7F, (byte) 0x7B,
			(byte) 0x5B, (byte) 0x6C, (byte) 0x50, (byte) 0x7D,
			(byte) 0x4D, (byte) 0x5D, (byte) 0x5C, (byte) 0x4E,
			(byte) 0x6B, (byte) 0x60, (byte) 0x4B, (byte) 0x61,
			(byte) 0xF0, (byte) 0xF1, (byte) 0xF2, (byte) 0xF3,
			(byte) 0xF4, (byte) 0xF5, (byte) 0xF6, (byte) 0xF7,
			(byte) 0xF8, (byte) 0xF9, (byte) 0x7A, (byte) 0x5E,
			(byte) 0x4C, (byte) 0x7E, (byte) 0x6E, (byte) 0x6F,
			(byte) 0x7C, (byte) 0xC1, (byte) 0xC2, (byte) 0xC3,
			(byte) 0xC4, (byte) 0xC5, (byte) 0xC6, (byte) 0xC7,
			(byte) 0xC8, (byte) 0xC9, (byte) 0xD1, (byte) 0xD2,
			(byte) 0xD3, (byte) 0xD4, (byte) 0xD5, (byte) 0xD6,
			(byte) 0xD7, (byte) 0xD8, (byte) 0xD9, (byte) 0xE2,
			(byte) 0xE3, (byte) 0xE4, (byte) 0xE5, (byte) 0xE6,
			(byte) 0xE7, (byte) 0xE8, (byte) 0xE9, (byte) 0xAD,
			(byte) 0xE0, (byte) 0xBD, (byte) 0x5F, (byte) 0x6D,
			(byte) 0x79, (byte) 0x81, (byte) 0x82, (byte) 0x83,
			(byte) 0x84, (byte) 0x85, (byte) 0x86, (byte) 0x87,
			(byte) 0x88, (byte) 0x89, (byte) 0x91, (byte) 0x92,
			(byte) 0x93, (byte) 0x94, (byte) 0x95, (byte) 0x96,
			(byte) 0x97, (byte) 0x98, (byte) 0x99, (byte) 0xA2,
			(byte) 0xA3, (byte) 0xA4, (byte) 0xA5, (byte) 0xA6,
			(byte) 0xA7, (byte) 0xA8, (byte) 0xA9, (byte) 0xC0,
			(byte) 0x4F, (byte) 0xD0, (byte) 0xA1, (byte) 0x7,
			(byte) 0x20, (byte) 0x21, (byte) 0x22, (byte) 0x23,
			(byte) 0x24, (byte) 0x25, (byte) 0x6, (byte) 0x17,
			(byte) 0x28, (byte) 0x29, (byte) 0x2A, (byte) 0x2B,
			(byte) 0x2C, (byte) 0x9, (byte) 0xA, (byte) 0x1B,
			(byte) 0x30, (byte) 0x31, (byte) 0x1A, (byte) 0x33,
			(byte) 0x34, (byte) 0x35, (byte) 0x36, (byte) 0x8,
			(byte) 0x38, (byte) 0x39, (byte) 0x3A, (byte) 0x3B,
			(byte) 0x4, (byte) 0x14, (byte) 0x3E, (byte) 0xFF,
			(byte) 0x41, (byte) 0xAA, (byte) 0x4A, (byte) 0xB1,
			(byte) 0x9F, (byte) 0xB2, (byte) 0x6A, (byte) 0xB5,
			(byte) 0xBB, (byte) 0xB4, (byte) 0x9A, (byte) 0x8A,
			(byte) 0xB0, (byte) 0xCA, (byte) 0xAF, (byte) 0xBC,
			(byte) 0x90, (byte) 0x8F, (byte) 0xEA, (byte) 0xFA,
			(byte) 0xBE, (byte) 0xA0, (byte) 0xB6, (byte) 0xB3,
			(byte) 0x9D, (byte) 0xDA, (byte) 0x9B, (byte) 0x8B,
			(byte) 0xB7, (byte) 0xB8, (byte) 0xB9, (byte) 0xAB,
			(byte) 0x64, (byte) 0x65, (byte) 0x62, (byte) 0x66,
			(byte) 0x63, (byte) 0x67, (byte) 0x9E, (byte) 0x68,
			(byte) 0x74, (byte) 0x71, (byte) 0x72, (byte) 0x73,
			(byte) 0x78, (byte) 0x75, (byte) 0x76, (byte) 0x77,
			(byte) 0xAC, (byte) 0x69, (byte) 0xED, (byte) 0xEE,
			(byte) 0xEB, (byte) 0xEF, (byte) 0xEC, (byte) 0xBF,
			(byte) 0x80, (byte) 0xFD, (byte) 0xFE, (byte) 0xFB,
			(byte) 0xFC, (byte) 0xBA, (byte) 0xAE, (byte) 0x59,
			(byte) 0x44, (byte) 0x45, (byte) 0x42, (byte) 0x46,
			(byte) 0x43, (byte) 0x47, (byte) 0x9C, (byte) 0x48,
			(byte) 0x54, (byte) 0x51, (byte) 0x52, (byte) 0x53,
			(byte) 0x58, (byte) 0x55, (byte) 0x56, (byte) 0x57,
			(byte) 0x8C, (byte) 0x49, (byte) 0xCD, (byte) 0xCE,
			(byte) 0xCB, (byte) 0xCF, (byte) 0xCC, (byte) 0xE1,
			(byte) 0x70, (byte) 0xDD, (byte) 0xDE, (byte) 0xDB,
			(byte) 0xDC, (byte) 0x8D, (byte) 0x8E, (byte) 0xDF
	};
	public static final byte STX = 0x02;
	public static final byte FS = 0x1C;
	public static final byte US = 0x1F;
	public static final byte RS = 0x1D;
	public static final byte GS = 0x1E;
	public static final byte ETX = 0x03;

	public static String ebcdicToAscii(byte[] e) {
		return new String(
				ebcdicToAsciiBytes(e, 0, e.length), CHARSET
		);
	}

	public static String ebcdicToAscii(byte[] e, int offset, int len) {
		return new String(
				ebcdicToAsciiBytes(e, offset, len), CHARSET
		);
	}

	public static byte[] ebcdicToAsciiBytes(byte[] e) {
		return ebcdicToAsciiBytes(e, 0, e.length);
	}

	public static byte[] ebcdicToAsciiBytes(byte[] e, int offset, int len) {
		byte[] a = new byte[len];
		for (int i = 0; i < len; i++)
			a[i] = EBCDIC2ASCII[e[offset + i] & 0xFF];
		return a;
	}

	public static byte[] asciiToEbcdic(String s) {
		int len = s.length();
		byte b[] = new byte[len];
		for (int i = 0; i < len; i++)
			b[i] = ASCII2EBCDIC[s.charAt(i) & 0xFF];
		return b;
	}

	public static byte[] asciiToEbcdic(byte[] a) {
		byte[] e = new byte[a.length];
		for (int i = 0; i < a.length; i++)
			e[i] = ASCII2EBCDIC[a[i] & 0xFF];
		return e;
	}

	public static void asciiToEbcdic(String s, byte[] e, int offset) {
		int len = s.length();
		for (int i = 0; i < len; i++)
			e[offset + i] = ASCII2EBCDIC[s.charAt(i) & 0xFF];
	}

	public static void asciiToEbcdic(byte[] s, byte[] e, int offset) {
		int len = s.length;
		for (int i = 0; i < len; i++)
			e[offset + i] = ASCII2EBCDIC[s[i]];
	}

	/**
	 * pad to the left
	 *
	 * @param s   - original string
	 * @param len - desired len
	 * @param c   - padding char
	 * @return padded string
	 * @throws ISOException on error
	 */
	public static String padleft(String s, int len, char c)
			throws ISOException {
		s = s.trim();
		if (s.length() > len)
			throw new ISOException("invalid len " + s.length() + "/" + len);
		StringBuilder d = new StringBuilder(len);
		int fill = len - s.length();
		while (fill-- > 0)
			d.append(c);
		d.append(s);
		return d.toString();
	}

	/**
	 * pad to the right
	 *
	 * @param s   -
	 *            original string
	 * @param len -
	 *            desired len
	 * @param c   -
	 *            padding char
	 * @return padded string
	 * @throws ISOException if String's length greater than pad length
	 */
	public static String padright(String s, int len, char c) throws ISOException {
		s = s.trim();
		if (s.length() > len)
			throw new ISOException("invalid len " + s.length() + "/" + len);
		StringBuilder d = new StringBuilder(len);
		int fill = len - s.length();
		d.append(s);
		while (fill-- > 0)
			d.append(c);
		return d.toString();
	}

	/**
	 * trim String (if not null)
	 *
	 * @param s String to trim
	 * @return String (may be null)
	 */
	public static String trim(String s) {
		return s != null ? s.trim() : null;
	}

	/**
	 * left pad with '0'
	 *
	 * @param s   - original string
	 * @param len - desired len
	 * @return zero padded string
	 * @throws ISOException if string's length greater than len
	 */
	public static String zeropad(String s, int len) throws ISOException {
		return padleft(s, len, '0');
	}

	/**
	 * zeropads a long without throwing an ISOException (performs modulus operation)
	 *
	 * @param l   the long
	 * @param len the length
	 * @return zeropadded value
	 */
	public static String zeropad(long l, int len) {
		try {
			return padleft(Long.toString((long) (l % Math.pow(10, len))), len, '0');
		} catch (ISOException ignored) {
		}
		return null; // should never happen
	}

	/**
	 * pads to the right
	 *
	 * @param s   - original string
	 * @param len - desired len
	 * @return space padded string
	 */
	public static String strpad(String s, int len) {
		StringBuilder d = new StringBuilder(s);
		while (d.length() < len)
			d.append(' ');
		return d.toString();
	}

	public static String zeropadRight(String s, int len) {
		StringBuilder d = new StringBuilder(s);
		while (d.length() < len)
			d.append('0');
		return d.toString();
	}

	/**
	 * converts to BCD
	 *
	 * @param s       - the number
	 * @param padLeft - flag indicating left/right padding
	 * @param d       The byte array to copy into.
	 * @param offset  Where to start copying into.
	 * @return BCD representation of the number
	 */
	public static byte[] str2bcd(String s, boolean padLeft, byte[] d, int offset) {
		int len = s.length();
		int start = (len & 1) == 1 && padLeft ? 1 : 0;
		for (int i = start; i < len + start; i++)
			d[offset + (i >> 1)] |= s.charAt(i - start) - '0' << ((i & 1) == 1 ? 0 : 4);
		return d;
	}

	/**
	 * converts to BCD
	 *
	 * @param s       - the number
	 * @param padLeft - flag indicating left/right padding
	 * @return BCD representation of the number
	 */
	public static byte[] str2bcd(String s, boolean padLeft) {
		int len = s.length();
		byte[] d = new byte[len + 1 >> 1];
		return str2bcd(s, padLeft, d, 0);
	}

	/**
	 * converts to BCD
	 *
	 * @param s       - the number
	 * @param padLeft - flag indicating left/right padding
	 * @param fill    - fill value
	 * @return BCD representation of the number
	 */
	public static byte[] str2bcd(String s, boolean padLeft, byte fill) {
		int len = s.length();
		byte[] d = new byte[len + 1 >> 1];
		Arrays.fill(d, fill);
		int start = (len & 1) == 1 && padLeft ? 1 : 0;
		for (int i = start; i < len + start; i++)
			d[i >> 1] |= s.charAt(i - start) - '0' << ((i & 1) == 1 ? 0 : 4);
		return d;
	}

	/**
	 * converts a BCD representation of a number to a String
	 *
	 * @param b       - BCD representation
	 * @param offset  - starting offset
	 * @param len     - BCD field len
	 * @param padLeft - was padLeft packed?
	 * @return the String representation of the number
	 */
	public static String bcd2str(byte[] b, int offset,
	                             int len, boolean padLeft) {
		StringBuilder d = new StringBuilder(len);
		int start = (len & 1) == 1 && padLeft ? 1 : 0;
		for (int i = start; i < len + start; i++) {
			int shift = (i & 1) == 1 ? 0 : 4;
			char c = Character.forDigit(
					b[offset + (i >> 1)] >> shift & 0x0F, 16);
			if (c == 'd')
				c = '=';
			d.append(Character.toUpperCase(c));
		}
		return d.toString();
	}

	/**
	 * converts a byte array to hex string
	 * (suitable for dumps and ASCII packaging of Binary fields
	 *
	 * @param b - byte array
	 * @return String representation
	 */
	public static String hexString(byte[] b) {
		StringBuilder d = new StringBuilder(b.length * 2);
		for (byte aB : b) {
			d.append(hexStrings[(int) aB & 0xFF]);
		}
		return d.toString();
	}

	/**
	 * converts a byte array to printable characters
	 *
	 * @param b - byte array
	 * @return String representation
	 */
	public static String dumpString(byte[] b) {
		StringBuilder d = new StringBuilder(b.length * 2);
		for (byte aB : b) {
			char c = (char) aB;
			if (Character.isISOControl(c)) {
				// TODO: complete list of control characters,
				// use a String[] instead of this weird switch
				switch (c) {
					case '\r':
						d.append("{CR}");
						break;
					case '\n':
						d.append("{LF}");
						break;
					case '\000':
						d.append("{NULL}");
						break;
					case '\001':
						d.append("{SOH}");
						break;
					case '\002':
						d.append("{STX}");
						break;
					case '\003':
						d.append("{ETX}");
						break;
					case '\004':
						d.append("{EOT}");
						break;
					case '\005':
						d.append("{ENQ}");
						break;
					case '\006':
						d.append("{ACK}");
						break;
					case '\007':
						d.append("{BEL}");
						break;
					case '\020':
						d.append("{DLE}");
						break;
					case '\025':
						d.append("{NAK}");
						break;
					case '\026':
						d.append("{SYN}");
						break;
					case '\034':
						d.append("{FS}");
						break;
					case '\036':
						d.append("{RS}");
						break;
					default:
						d.append('[');
						d.append(hexStrings[(int) aB & 0xFF]);
						d.append(']');
						break;
				}
			} else
				d.append(c);

		}
		return d.toString();
	}

	/**
	 * converts a byte array to hex string
	 * (suitable for dumps and ASCII packaging of Binary fields
	 *
	 * @param b      - byte array
	 * @param offset - starting position
	 * @param len    the length
	 * @return String representation
	 */
	public static String hexString(byte[] b, int offset, int len) {
		StringBuilder d = new StringBuilder(len * 2);
		len += offset;
		for (int i = offset; i < len; i++) {
			d.append(hexStrings[(int) b[i] & 0xFF]);
		}
		return d.toString();
	}

	/**
	 * bit representation of a BitSet
	 * suitable for dumps and debugging
	 *
	 * @param b - the BitSet
	 * @return string representing the bits (i.e. 011010010...)
	 */
	public static String bitSet2String(BitSet b) {
		int len = b.size();
		len = len > 128 ? 128 : len;
		StringBuilder d = new StringBuilder(len);
		for (int i = 0; i < len; i++)
			d.append(b.get(i) ? '1' : '0');
		return d.toString();
	}

	/**
	 * converts a BitSet into a binary field
	 * used in pack routines
	 *
	 * @param b - the BitSet
	 * @return binary representation
	 */
	public static byte[] bitSet2byte(BitSet b) {
		int len = b.length() + 62 >> 6 << 6;
		byte[] d = new byte[len >> 3];
		for (int i = 0; i < len; i++)
			if (b.get(i + 1))
				d[i >> 3] |= 0x80 >> i % 8;
		if (len > 64)
			d[0] |= 0x80;
		if (len > 128)
			d[8] |= 0x80;
		return d;
	}

	/**
	 * converts a BitSet into a binary field
	 * used in pack routines
	 *
	 * @param b     - the BitSet
	 * @param bytes - number of bytes to return
	 * @return binary representation
	 */
	public static byte[] bitSet2byte(BitSet b, int bytes) {
		int len = bytes * 8;

		byte[] d = new byte[bytes];
		for (int i = 0; i < len; i++)
			if (b.get(i + 1))
				d[i >> 3] |= 0x80 >> i % 8;
		//TODO: review why 2nd & 3rd bit map flags are set here???
		if (len > 64)
			d[0] |= 0x80;
		if (len > 128)
			d[8] |= 0x80;
		return d;
	}

	/*
	 * Convert BitSet to int value.
	 */
	public static int bitSet2Int(BitSet bs) {
		int total = 0;
		int b = bs.length() - 1;
		if (b > 0) {
			int value = (int) Math.pow(2, b);
			for (int i = 0; i <= b; i++) {
				if (bs.get(i))
					total += value;
				value = value >> 1;
			}
		}

		return total;
	}

	/*
	 * Convert int value to BitSet.
	 */
	public static BitSet int2BitSet(int value) {

		return int2BitSet(value, 0);
	}

	/*
	 * Convert int value to BitSet.
	 */
	public static BitSet int2BitSet(int value, int offset) {

		BitSet bs = new BitSet();

		String hex = Integer.toHexString(value);
		hex2BitSet(bs, hex.getBytes(), offset);

		return bs;
	}

	/**
	 * Converts a binary representation of a Bitmap field
	 * into a Java BitSet
	 *
	 * @param b                    - binary representation
	 * @param offset               - staring offset
	 * @param bitZeroMeansExtended - true for ISO-8583
	 * @return java BitSet object
	 */
	public static BitSet byte2BitSet
	(byte[] b, int offset, boolean bitZeroMeansExtended) {
		int len = bitZeroMeansExtended ?
				(b[offset] & 0x80) == 0x80 ? 128 : 64 : 64;
		BitSet bmap = new BitSet(len);
		for (int i = 0; i < len; i++)
			if ((b[offset + (i >> 3)] & 0x80 >> i % 8) > 0)
				bmap.set(i + 1);
		return bmap;
	}

	/**
	 * Converts a binary representation of a Bitmap field
	 * into a Java BitSet
	 *
	 * @param b       - binary representation
	 * @param offset  - staring offset
	 * @param maxBits - max number of bits (supports 64,128 or 192)
	 * @return java BitSet object
	 */
	public static BitSet byte2BitSet(byte[] b, int offset, int maxBits) {
		int len = maxBits > 64 ?
				(b[offset] & 0x80) == 0x80 ? 128 : 64 : maxBits;

		if (maxBits > 128 &&
				b.length > offset + 8 &&
				(b[offset + 8] & 0x80) == 0x80) {
			len = 192;
		}
		BitSet bmap = new BitSet(len);
		for (int i = 0; i < len; i++)
			if ((b[offset + (i >> 3)] & 0x80 >> i % 8) > 0)
				bmap.set(i + 1);
		return bmap;
	}

	/**
	 * Converts a binary representation of a Bitmap field
	 * into a Java BitSet
	 *
	 * @param bmap      - BitSet
	 * @param b         - hex representation
	 * @param bitOffset - (i.e. 0 for primary bitmap, 64 for secondary)
	 * @return java BitSet object
	 */
	public static BitSet byte2BitSet(BitSet bmap, byte[] b, int bitOffset) {
		int len = b.length << 3;
		for (int i = 0; i < len; i++)
			if ((b[i >> 3] & 0x80 >> i % 8) > 0)
				bmap.set(bitOffset + i + 1);
		return bmap;
	}

	/**
	 * Converts an ASCII representation of a Bitmap field
	 * into a Java BitSet
	 *
	 * @param b                    - hex representation
	 * @param offset               - starting offset
	 * @param bitZeroMeansExtended - true for ISO-8583
	 * @return java BitSet object
	 */
	public static BitSet hex2BitSet
	(byte[] b, int offset, boolean bitZeroMeansExtended) {
		int len = bitZeroMeansExtended ?
				(Character.digit((char) b[offset], 16) & 0x08) == 8 ? 128 : 64 :
				64;
		BitSet bmap = new BitSet(len);
		for (int i = 0; i < len; i++) {
			int digit = Character.digit((char) b[offset + (i >> 2)], 16);
			if ((digit & 0x08 >> i % 4) > 0)
				bmap.set(i + 1);
		}
		return bmap;
	}

	/**
	 * Converts an ASCII representation of a Bitmap field
	 * into a Java BitSet
	 *
	 * @param b       - hex representation
	 * @param offset  - starting offset
	 * @param maxBits - max number of bits (supports 8, 16, 24, 32, 48, 52, 64,.. 128 or 192)
	 * @return java BitSet object
	 */
	public static BitSet hex2BitSet(byte[] b, int offset, int maxBits) {
		int len = maxBits > 64 ?
				(Character.digit((char) b[offset], 16) & 0x08) == 8 ? 128 : 64 :
				maxBits;
		if (len > 64 && maxBits > 128 &&
				b.length > offset + 16 &&
				(Character.digit((char) b[offset + 16], 16) & 0x08) == 8) {
			len = 192;
		}
		BitSet bmap = new BitSet(len);
		for (int i = 0; i < len; i++) {
			int digit = Character.digit((char) b[offset + (i >> 2)], 16);
			if ((digit & 0x08 >> i % 4) > 0) {
				bmap.set(i + 1);
				if (i == 65 && maxBits > 128)
					len = 192;
			}
		}
		return bmap;
	}

	/**
	 * Converts an ASCII representation of a Bitmap field
	 * into a Java BitSet
	 *
	 * @param bmap      - BitSet
	 * @param b         - hex representation
	 * @param bitOffset - (i.e. 0 for primary bitmap, 64 for secondary)
	 * @return java BitSet object
	 */
	public static BitSet hex2BitSet(BitSet bmap, byte[] b, int bitOffset) {
		int len = b.length << 2;
		for (int i = 0; i < len; i++) {
			int digit = Character.digit((char) b[i >> 2], 16);
			if ((digit & 0x08 >> i % 4) > 0)
				bmap.set(bitOffset + i + 1);
		}
		return bmap;
	}

	/**
	 * @param b      source byte array
	 * @param offset starting offset
	 * @param len    number of bytes in destination (processes len*2)
	 * @return byte[len]
	 */
	public static byte[] hex2byte(byte[] b, int offset, int len) {
		byte[] d = new byte[len];
		for (int i = 0; i < len * 2; i++) {
			int shift = i % 2 == 1 ? 0 : 4;
			d[i >> 1] |= Character.digit((char) b[offset + i], 16) << shift;
		}
		return d;
	}

	/**
	 * Converts a hex string into a byte array
	 *
	 * @param s source string (with Hex representation)
	 * @return byte array
	 */
	public static byte[] hex2byte(String s) {
		if (s.length() % 2 == 0) {
			return hex2byte(s.getBytes(), 0, s.length() >> 1);
		} else {
			// Padding left zero to make it even size #Bug raised by tommy
			return hex2byte("0" + s);
		}
	}

	/**
	 * Converts a byte array into a hex string
	 *
	 * @param bs source byte array
	 * @return hexadecimal representation of bytes
	 */
	public static String byte2hex(byte[] bs) {
		return byte2hex(bs, 0, bs.length);
	}

	/**
	 * Converts an integer into a byte array of hex
	 *
	 * @param value
	 * @return bytes representation of integer
	 */
	public static byte[] int2byte(int value) {
		if (value < 0) {
			return new byte[]{(byte) (value >>> 24 & 0xFF), (byte) (value >>> 16 & 0xFF),
					(byte) (value >>> 8 & 0xFF), (byte) (value & 0xFF)};
		} else if (value <= 0xFF) {
			return new byte[]{(byte) (value & 0xFF)};
		} else if (value <= 0xFFFF) {
			return new byte[]{(byte) (value >>> 8 & 0xFF), (byte) (value & 0xFF)};
		} else if (value <= 0xFFFFFF) {
			return new byte[]{(byte) (value >>> 16 & 0xFF), (byte) (value >>> 8 & 0xFF),
					(byte) (value & 0xFF)};
		} else {
			return new byte[]{(byte) (value >>> 24 & 0xFF), (byte) (value >>> 16 & 0xFF),
					(byte) (value >>> 8 & 0xFF), (byte) (value & 0xFF)};
		}
	}

	/**
	 * Converts a byte array of hex into an integer
	 *
	 * @param bytes
	 * @return integer representation of bytes
	 */
	public static int byte2int(byte[] bytes) {
		if (bytes == null || bytes.length == 0) {
			return 0;
		}
		ByteBuffer byteBuffer = ByteBuffer.allocate(4);
		for (int i = 0; i < 4 - bytes.length; i++) {
			byteBuffer.put((byte) 0);
		}
		for (int i = 0; i < bytes.length; i++) {
			byteBuffer.put(bytes[i]);
		}
		byteBuffer.position(0);
		return byteBuffer.getInt();
	}

	/**
	 * Converts a byte array into a string of lower case hex chars.
	 *
	 * @param bs     A byte array
	 * @param off    The index of the first byte to read
	 * @param length The number of bytes to read.
	 * @return the string of hex chars.
	 */
	public static String byte2hex(byte[] bs, int off, int length) {
		if (bs.length <= off || bs.length < off + length)
			throw new IllegalArgumentException();
		StringBuilder sb = new StringBuilder(length * 2);
		byte2hexAppend(bs, off, length, sb);
		return sb.toString();
	}

	private static void byte2hexAppend(byte[] bs, int off, int length, StringBuilder sb) {
		if (bs.length <= off || bs.length < off + length)
			throw new IllegalArgumentException();
		sb.ensureCapacity(sb.length() + length * 2);
		for (int i = off; i < off + length; i++) {
			sb.append(Character.forDigit(bs[i] >>> 4 & 0xf, 16));
			sb.append(Character.forDigit(bs[i] & 0xf, 16));
		}
	}

	/**
	 * format double value
	 *
	 * @param d   the amount
	 * @param len the field len
	 * @return a String of fieldLen characters (right justified)
	 */
	public static String formatDouble(double d, int len) {
		String prefix = Long.toString((long) d);
		String suffix = Integer.toString(
				(int) (Math.round(d * 100f) % 100));
		try {
			if (len > 3)
				prefix = ISOUtil.padleft(prefix, len - 3, ' ');
			suffix = ISOUtil.zeropad(suffix, 2);
		} catch (ISOException e) {
			// should not happen
		}
		return prefix + "." + suffix;
	}

	/**
	 * prepare long value used as amount for display
	 * (implicit 2 decimals)
	 *
	 * @param l   value
	 * @param len display len
	 * @return formated field
	 * @throws ISOException
	 */
	public static String formatAmount(long l, int len) throws ISOException {
		String buf = Long.toString(l);
		if (l < 100)
			buf = zeropad(buf, 3);
		StringBuilder s = new StringBuilder(padleft(buf, len - 1, ' '));
		s.insert(len - 3, '.');
		return s.toString();
	}

	/**
	 * XML normalizer
	 *
	 * @param s         source String
	 * @param canonical true if we want to normalize \r and \n as well
	 * @return normalized string suitable for XML Output
	 */
	public static String normalize(String s, boolean canonical) {
		StringBuilder str = new StringBuilder();

		int len = s != null ? s.length() : 0;
		for (int i = 0; i < len; i++) {
			char ch = s.charAt(i);
			switch (ch) {
				case '<':
					str.append("&lt;");
					break;
				case '>':
					str.append("&gt;");
					break;
				case '&':
					str.append("&amp;");
					break;
				case '"':
					str.append("&quot;");
					break;
				case '\r':
				case '\n':
					if (canonical) {
						str.append("&#");
						str.append(Integer.toString(ch & 0xFF));
						str.append(';');
						break;
					}
					// else, default append char
				default:
					if (ch < 0x20) {
						str.append("&#");
						str.append(Integer.toString(ch & 0xFF));
						str.append(';');
					} else if (ch > 0xff00) {
						str.append((char) (ch & 0xFF));
					} else
						str.append(ch);
			}
		}
		return str.toString();
	}

	/**
	 * XML normalizer (default canonical)
	 *
	 * @param s source String
	 * @return normalized string suitable for XML Output
	 */
	public static String normalize(String s) {
		return normalize(s, true);
	}

	/**
	 * Protects PAN, Track2, CVC (suitable for logs).
	 * <p/>
	 * <pre>
	 * "40000101010001" is converted to "400001____0001"
	 * "40000101010001=020128375" is converted to "400001____0001=0201_____"
	 * "40000101010001D020128375" is converted to "400001____0001D0201_____"
	 * "123" is converted to "___"
	 * </pre>
	 *
	 * @param s string to be protected
	 * @return 'protected' String
	 */
	public static String protect(String s) {
		StringBuilder sb = new StringBuilder();
		int len = s.length();
		int clear = len > 6 ? 6 : 0;
		int lastFourIndex = -1;
		if (clear > 0) {
			lastFourIndex = s.indexOf('=') - 4;
			if (lastFourIndex < 0)
				lastFourIndex = s.indexOf('^') - 4;
			if (lastFourIndex < 0 && s.indexOf('^') < 0)
				lastFourIndex = s.indexOf('D') - 4;
			if (lastFourIndex < 0)
				lastFourIndex = len - 4;
		}
		for (int i = 0; i < len; i++) {
			if (s.charAt(i) == '=' || s.charAt(i) == 'D' && s.indexOf('^') < 0)
				clear = 1;  // use clear=5 to keep the expiration date
			else if (s.charAt(i) == '^') {
				lastFourIndex = 0;
				clear = len - i;
			} else if (i == lastFourIndex)
				clear = 4;
			sb.append(clear-- > 0 ? s.charAt(i) : '_');
		}
		s = sb.toString();
		try {
			//Addresses Track1 Truncation
			int charCount = s.replaceAll("[^\\^]", "").length();
			if (charCount == 2) {
				s = s.substring(0, s.lastIndexOf("^") + 1);
				s = ISOUtil.padright(s, len, '_');
			}
		} catch (ISOException e) {
			//cannot PAD - should never get here
		}
		return s;
	}

	public static int[] toIntArray(String s) {
		StringTokenizer st = new StringTokenizer(s);
		int[] array = new int[st.countTokens()];
		for (int i = 0; st.hasMoreTokens(); i++)
			array[i] = Integer.parseInt(st.nextToken());
		return array;
	}

	public static String[] toStringArray(String s) {
		StringTokenizer st = new StringTokenizer(s);
		String[] array = new String[st.countTokens()];
		for (int i = 0; st.hasMoreTokens(); i++)
			array[i] = st.nextToken();
		return array;
	}

	/**
	 * Bitwise XOR between corresponding bytes
	 *
	 * @param op1 byteArray1
	 * @param op2 byteArray2
	 * @return an array of length = the smallest between op1 and op2
	 */
	public static byte[] xor(byte[] op1, byte[] op2) {
		byte[] result;
		// Use the smallest array
		if (op2.length > op1.length) {
			result = new byte[op1.length];
		} else {
			result = new byte[op2.length];
		}
		for (int i = 0; i < result.length; i++) {
			result[i] = (byte) (op1[i] ^ op2[i]);
		}
		return result;
	}

	/**
	 * Bitwise XOR between corresponding byte arrays represented in hex
	 *
	 * @param op1 hexstring 1
	 * @param op2 hexstring 2
	 * @return an array of length = the smallest between op1 and op2
	 */
	public static String hexor(String op1, String op2) {
		byte[] xor = xor(hex2byte(op1), hex2byte(op2));
		return hexString(xor);
	}

	/**
	 * Trims a byte[] to a certain length
	 *
	 * @param array  the byte[] to be trimmed
	 * @param length the wanted length
	 * @return the trimmed byte[]
	 */
	public static byte[] trim(byte[] array, int length) {
		byte[] trimmedArray = new byte[length];
		System.arraycopy(array, 0, trimmedArray, 0, length);
		return trimmedArray;
	}

	/**
	 * Concatenates two byte arrays (array1 and array2)
	 *
	 * @param array1 first part
	 * @param array2 last part
	 * @return the concatenated array
	 */
	public static byte[] concat(byte[] array1, byte[] array2) {
		byte[] concatArray = new byte[array1.length + array2.length];
		System.arraycopy(array1, 0, concatArray, 0, array1.length);
		System.arraycopy(array2, 0, concatArray, array1.length, array2.length);
		return concatArray;
	}

	/**
	 * Concatenates two byte arrays (array1 and array2)
	 *
	 * @param array1      first part
	 * @param beginIndex1 initial index
	 * @param length1     length
	 * @param array2      last part
	 * @param beginIndex2 last part index
	 * @param length2     last part length
	 * @return the concatenated array
	 */
	public static byte[] concat(byte[] array1, int beginIndex1, int length1, byte[] array2,
	                            int beginIndex2, int length2) {
		byte[] concatArray = new byte[length1 + length2];
		System.arraycopy(array1, beginIndex1, concatArray, 0, length1);
		System.arraycopy(array2, beginIndex2, concatArray, length1, length2);
		return concatArray;
	}

	/**
	 * Causes the currently executing thread to sleep (temporarily cease
	 * execution) for the specified number of milliseconds. The thread
	 * does not lose ownership of any monitors.
	 * <p/>
	 * This is the same as Thread.sleep () without throwing InterruptedException
	 *
	 * @param millis the length of time to sleep in milliseconds.
	 */
	public static void sleep(long millis) {
		try {
			Thread.sleep(millis);
		} catch (InterruptedException ignored) {
		}
	}

	/**
	 * Left unPad with '0'
	 *
	 * @param s - original string
	 * @return zero unPadded string
	 */
	public static String zeroUnPad(String s) {
		return unPadLeft(s, '0');
	}

	/**
	 * Right unPad with ' '
	 *
	 * @param s - original string
	 * @return blank unPadded string
	 */
	public static String blankUnPad(String s) {
		return unPadRight(s, ' ');
	}

	/**
	 * Unpad from right.
	 *
	 * @param s - original string
	 * @param c - padding char
	 * @return unPadded string.
	 */
	public static String unPadRight(String s, char c) {
		int end = s.length();
		if (end == 0)
			return s;
		while (0 < end && s.charAt(end - 1) == c) end--;
		return 0 < end ? s.substring(0, end) : s.substring(0, 1);
	}

	/**
	 * Unpad from left.
	 *
	 * @param s - original string
	 * @param c - padding char
	 * @return unPadded string.
	 */
	public static String unPadLeft(String s, char c) {
		int fill = 0, end = s.length();
		if (end == 0)
			return s;
		while (fill < end && s.charAt(fill) == c) fill++;
		return fill < end ? s.substring(fill, end) : s.substring(fill - 1, end);
	}

	/**
	 * @return true if the string is zero-filled ( 0 char filled )
	 **/
	public static boolean isZero(String s) {
		int i = 0, len = s.length();
		while (i < len && s.charAt(i) == '0') {
			i++;
		}
		return i >= len;
	}

	/**
	 * @return true if the string is blank filled (space char filled)
	 */
	public static boolean isBlank(String s) {
		return s.trim().length() == 0;
	}

	/**
	 * Return true if the string is alphanum.
	 * <code>{letter digit (.) (_) (-) ( ) (?) }</code>
	 **/
	public static boolean isAlphaNumeric(String s) {
		int i = 0, len = s.length();
		while (i < len && (Character.isLetterOrDigit(s.charAt(i)) ||
				s.charAt(i) == ' ' || s.charAt(i) == '.' ||
				s.charAt(i) == '-' || s.charAt(i) == '_')
				|| s.charAt(i) == '?') {
			i++;
		}
		return i >= len;
	}

	/**
	 * Return true if the string represent a number
	 * in the specified radix.
	 * <br><br>
	 **/
	public static boolean isNumeric(String s, int radix) {
		int i = 0, len = s.length();
		while (i < len && Character.digit(s.charAt(i), radix) > -1) {
			i++;
		}
		return i >= len && len > 0;
	}

	/**
	 * Converts a BitSet into an extended binary field
	 * used in pack routines. The result is always in the
	 * extended format: (16 bytes of length)
	 * <br><br>
	 *
	 * @param b the BitSet
	 * @return binary representation
	 */
	public static byte[] bitSet2extendedByte(BitSet b) {
		int len = 128;
		byte[] d = new byte[len >> 3];
		for (int i = 0; i < len; i++)
			if (b.get(i + 1))
				d[i >> 3] |= 0x80 >> i % 8;
		d[0] |= 0x80;
		return d;
	}

	/**
	 * Converts a String to an integer of base radix.
	 * <br><br>
	 * String constraints are:
	 * <li>Number must be less than 10 digits</li>
	 * <li>Number must be positive</li>
	 *
	 * @param s     String representation of number
	 * @param radix Number base to use
	 * @return integer value of number
	 * @throws NumberFormatException
	 */
	public static int parseInt(String s, int radix) throws NumberFormatException {
		int length = s.length();
		if (length > 9)
			throw new NumberFormatException("Number can have maximum 9 digits");
		int result;
		int index = 0;
		int digit = Character.digit(s.charAt(index++), radix);
		if (digit == -1)
			throw new NumberFormatException("String contains non-digit");
		result = digit;
		while (index < length) {
			result *= radix;
			digit = Character.digit(s.charAt(index++), radix);
			if (digit == -1)
				throw new NumberFormatException("String contains non-digit");
			result += digit;
		}
		return result;
	}

	/**
	 * Converts a String to an integer of radix 10.
	 * <br><br>
	 * String constraints are:
	 * <li>Number must be less than 10 digits</li>
	 * <li>Number must be positive</li>
	 *
	 * @param s String representation of number
	 * @return integer value of number
	 * @throws NumberFormatException
	 */
	public static int parseInt(String s) throws NumberFormatException {
		return parseInt(s, 10);
	}

	/**
	 * Converts a character array to an integer of base radix.
	 * <br><br>
	 * Array constraints are:
	 * <li>Number must be less than 10 digits</li>
	 * <li>Number must be positive</li>
	 *
	 * @param cArray Character Array representation of number
	 * @param radix  Number base to use
	 * @return integer value of number
	 * @throws NumberFormatException
	 */
	public static int parseInt(char[] cArray, int radix) throws NumberFormatException {
		int length = cArray.length;
		if (length > 9)
			throw new NumberFormatException("Number can have maximum 9 digits");
		int result;
		int index = 0;
		int digit = Character.digit(cArray[index++], radix);
		if (digit == -1)
			throw new NumberFormatException("Char array contains non-digit");
		result = digit;
		while (index < length) {
			result *= radix;
			digit = Character.digit(cArray[index++], radix);
			if (digit == -1)
				throw new NumberFormatException("Char array contains non-digit");
			result += digit;
		}
		return result;
	}

	/**
	 * Converts a character array to an integer of radix 10.
	 * <br><br>
	 * Array constraints are:
	 * <li>Number must be less than 10 digits</li>
	 * <li>Number must be positive</li>
	 *
	 * @param cArray Character Array representation of number
	 * @return integer value of number
	 * @throws NumberFormatException
	 */
	public static int parseInt(char[] cArray) throws NumberFormatException {
		return parseInt(cArray, 10);
	}

	/**
	 * Converts a byte array to an integer of base radix.
	 * <br><br>
	 * Array constraints are:
	 * <li>Number must be less than 10 digits</li>
	 * <li>Number must be positive</li>
	 *
	 * @param bArray Byte Array representation of number
	 * @param radix  Number base to use
	 * @return integer value of number
	 * @throws NumberFormatException
	 */
	public static int parseInt(byte[] bArray, int radix) throws NumberFormatException {
		int length = bArray.length;
		if (length > 9)
			throw new NumberFormatException("Number can have maximum 9 digits");
		int result;
		int index = 0;
		int digit = Character.digit((char) bArray[index++], radix);
		if (digit == -1)
			throw new NumberFormatException("Byte array contains non-digit");
		result = digit;
		while (index < length) {
			result *= radix;
			digit = Character.digit((char) bArray[index++], radix);
			if (digit == -1)
				throw new NumberFormatException("Byte array contains non-digit");
			result += digit;
		}
		return result;
	}

	/**
	 * Converts a byte array to an integer of radix 10.
	 * <br><br>
	 * Array constraints are:
	 * <li>Number must be less than 10 digits</li>
	 * <li>Number must be positive</li>
	 *
	 * @param bArray Byte Array representation of number
	 * @return integer value of number
	 * @throws NumberFormatException
	 */
	public static int parseInt(byte[] bArray) throws NumberFormatException {
		return parseInt(bArray, 10);
	}

	private static String hexOffset(int i) {
		i = i >> 4 << 4;
		int w = i > 0xFFFF ? 8 : 4;
		try {
			return zeropad(Integer.toString(i, 16), w);
		} catch (ISOException e) {
			// should not happen
			return e.getMessage();
		}
	}

	/**
	 * @param b a byte[] buffer
	 * @return hexdump
	 */
	public static String hexdump(byte[] b) {
		return hexdump(b, 0, b.length);
	}

	/**
	 * @param b      a byte[] buffer
	 * @param offset starting offset
	 */
	public static String hexdump(byte[] b, int offset) {
		return hexdump(b, offset, b.length - offset);
	}

	/**
	 * @param b      a byte[] buffer
	 * @param offset starting offset
	 * @param len    the Length
	 * @return hexdump
	 */
	public static String hexdump(byte[] b, int offset, int len) {
		StringBuilder sb = new StringBuilder();
		StringBuilder hex = new StringBuilder();
		StringBuilder ascii = new StringBuilder();
		String sep = "  ";
		String lineSep = System.getProperty("line.separator");
		len = offset + len;

		for (int i = offset; i < len; i++) {
			hex.append(hexStrings[(int) b[i] & 0xFF]);
			hex.append(' ');
			char c = (char) b[i];
			ascii.append(c >= 32 && c < 127 ? c : '.');

			int j = i % 16;
			switch (j) {
				case 7:
					hex.append(' ');
					break;
				case 15:
					sb.append(hexOffset(i));
					sb.append(sep);
					sb.append(hex.toString());
					sb.append(' ');
					sb.append(ascii.toString());
					sb.append(lineSep);
					hex = new StringBuilder();
					ascii = new StringBuilder();
					break;
			}
		}
		if (hex.length() > 0) {
			while (hex.length() < 49)
				hex.append(' ');

			sb.append(hexOffset(len));
			sb.append(sep);
			sb.append(hex.toString());
			sb.append(' ');
			sb.append(ascii.toString());
			sb.append(lineSep);
		}
		return sb.toString();
	}

	/**
	 * pads a string with 'F's (useful for pinoffset management)
	 *
	 * @param s   an [hex]string
	 * @param len desired length
	 * @return string right padded with 'F's
	 */
	public static String strpadf(String s, int len) {
		StringBuilder d = new StringBuilder(s);
		while (d.length() < len)
			d.append('F');
		return d.toString();
	}

	/**
	 * reverse the effect of strpadf
	 *
	 * @param s F padded string
	 * @return trimmed string
	 */
	public static String trimf(String s) {
		if (s != null) {
			int l = s.length();
			if (l > 0) {
				while (--l >= 0) {
					if (s.charAt(l) != 'F')
						break;
				}
				s = l == 0 ? "" : s.substring(0, l + 1);
			}
		}
		return s;
	}

	/**
	 * return the last n characters of the passed String, left padding where required with 0
	 *
	 * @param s String to take from
	 * @param n nuber of characters to take
	 * @return String (may be null)
	 */
	public static String takeLastN(String s, int n) throws ISOException {
		if (s.length() > n) {
			return s.substring(s.length() - n);
		} else {
			if (s.length() < n) {
				return zeropad(s, n);
			} else {
				return s;
			}
		}
	}

	/**
	 * return the first n characters of the passed String, left padding where required with 0
	 *
	 * @param s String to take from
	 * @param n nuber of characters to take
	 * @return String (may be null)
	 */
	public static String takeFirstN(String s, int n) throws ISOException {
		if (s.length() > n) {
			return s.substring(0, n);
		} else {
			if (s.length() < n) {
				return zeropad(s, n);
			} else {
				return s;
			}
		}
	}

	public static String millisToString(long millis) {
		StringBuilder sb = new StringBuilder();
		if (millis < 0) {
			millis = -millis;
			sb.append('-');
		}
		int ms = (int) (millis % 1000);
		millis /= 1000;
		int dd = (int) (millis / 86400);
		millis -= dd * 86400;
		int hh = (int) (millis / 3600);
		millis -= hh * 3600;
		int mm = (int) (millis / 60);
		millis -= mm * 60;
		int ss = (int) millis;
		if (dd > 0) {
			sb.append(Long.toString(dd));
			sb.append("d ");
		}
		sb.append(zeropad(hh, 2));
		sb.append(':');
		sb.append(zeropad(mm, 2));
		sb.append(':');
		sb.append(zeropad(ss, 2));
		sb.append('.');
		sb.append(zeropad(ms, 3));
		return sb.toString();
	}

	/**
	 * Format a string containing a amount conversion rate in the proper format
	 * <p/>
	 * Format:
	 * The leftmost digit (i.e., position 1) of this data element denotes the number of
	 * positions the decimal separator must be moved from the right. Positions 2–8 of
	 * this data element specify the rate. For example, a conversion rate value of
	 * 91234567 in this data element would equate to 0.001234567.
	 *
	 * @param convRate - amount conversion rate
	 * @return a string containing a amount conversion rate in the proper format,
	 * witch is suitable for create fields 10 and 11
	 * @throws ISOException
	 */
	public static String formatAmountConversionRate(double convRate) throws ISOException {
		if (convRate == 0)
			return null;
		BigDecimal cr = new BigDecimal(convRate);
		int x = 7 - cr.precision() + cr.scale();
		String bds = cr.movePointRight(cr.scale()).toString();
		if (x > 9)
			bds = ISOUtil.zeropad(bds, bds.length() + x - 9);
		String ret = ISOUtil.zeropadRight(bds, 7);
		return Math.min(9, x) + ISOUtil.takeFirstN(ret, 7);
	}

	/**
	 * Parse currency amount conversion rate string
	 * <p/>
	 * Suitble for parse fields 10 and 11
	 *
	 * @param convRate amount conversation rate
	 * @return parsed currency amount conversation rate
	 * @throws IllegalArgumentException
	 */
	public static double parseAmountConversionRate(String convRate) {
		if (convRate == null || convRate.length() != 8)
			throw new IllegalArgumentException("Invalid amount converion rate argument: '" +
					convRate + "'");
		BigDecimal bd = new BigDecimal(convRate);
		int pow = bd.movePointLeft(7).intValue();
		bd = new BigDecimal(convRate.substring(1));
		return bd.movePointLeft(pow).doubleValue();
	}

	/**
	 * Converts a string[] into a comma-delimited String.
	 * <p/>
	 * Takes care of escaping commas using a backlash
	 *
	 * @param ss string array to be comma encoded
	 * @return comma encoded string
	 * @see org.jpos.iso.ISOUtil#commaDecode(String)
	 */
	public static String commaEncode(String[] ss) {
		StringBuilder sb = new StringBuilder();
		for (String s : ss) {
			if (sb.length() > 0)
				sb.append(',');
			if (s != null) {
				for (int i = 0; i < s.length(); i++) {
					char c = s.charAt(i);
					switch (c) {
						case '\\':
						case ',':
							sb.append('\\');
							break;
					}
					sb.append(c);
				}
			}
		}
		return sb.toString();
	}

	/**
	 * Decodes a comma encoded String as encoded by commaEncode
	 *
	 * @param s the command encoded String
	 * @return String[]
	 * @see org.jpos.iso.ISOUtil#commaEncode(String[])
	 */
	public static String[] commaDecode(String s) {
		List<String> l = new ArrayList<String>();
		StringBuilder sb = new StringBuilder();
		boolean escaped = false;
		for (int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);
			if (!escaped) {
				switch (c) {
					case '\\':
						escaped = true;
						continue;
					case ',':
						l.add(sb.toString());
						sb = new StringBuilder();
						continue;
				}
			}
			sb.append(c);
			escaped = false;
		}
		if (sb.length() > 0)
			l.add(sb.toString());
		return l.toArray(new String[l.size()]);
	}

	/**
	 * Decodes a comma encoded String returning element in position i
	 *
	 * @param s comma encoded string
	 * @param i position (starts at 0)
	 * @return element in position i of comma encoded string, or null
	 */
	public static String commaDecode(String s, int i) {
		String[] ss = commaDecode(s);
		int l = ss.length;
		return i >= 0 && i < l ? ss[i] : null;
	}

	/**
	 * Compute card's check digit (LUHN)
	 *
	 * @param p PAN (without checkdigit)
	 * @return the checkdigit
	 */
	public static char calcLUHN(String p) {
		int i, crc;
		int odd = p.length() % 2;

		for (i = crc = 0; i < p.length(); i++) {
			char c = p.charAt(i);
			if (!Character.isDigit(c)) {
				throw new IllegalArgumentException("Invalid PAN " + p);
			}
			c = (char) (c - '0');
			if (i % 2 != odd)
				crc += c * 2 >= 10 ? c * 2 - 9 : c * 2;
			else
				crc += c;
		}

		return (char) ((crc % 10 == 0 ? 0 : 10 - crc % 10) + '0');
	}

	public static String getRandomDigits(Random r, int l, int radix) {
		StringBuilder sb = new StringBuilder();
		for (int i = 0; i < l; i++) {
			sb.append(r.nextInt(radix));
		}
		return sb.toString();
	}

	// See http://stackoverflow.com/questions/3263892/format-file-size-as-mb-gb-etc
	// and http://physics.nist.gov/cuu/Units/binary.html
	public static String readableFileSize(long size) {
		if (size <= 0) return "0";
		final String[] units = new String[]{"Bi", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"};
		int digitGroups = (int) (Math.log10(size) / Math.log10(1024));
		return new DecimalFormat("#,##0.#").format(size / Math.pow(1024, digitGroups)) + " " + units[digitGroups];
	}
}
